The present invention relates to network management and, more particularly, to a system and method for passive quality of service monitoring of a network.
As conventional networks have grown in size and complexity, the need for centralized management has grown. Part of that need for centralized management is the need for the policing of service level agreements for data transfer technologies, such as frame relay networks, to monitor quality of parameters. The quality of service parameters measure such values as one way packet travel time and the percentage of successful transmission of packet frames.
Customers of data delivery services are typically interested in monitoring quality of service parameters for the data network operated by a service provider in order to determine that the quality of delivery service they receive meets specific quantitative criteria. Two such quantitative criteria are one way packet transport latency and frequency of incidents of packet loss. Both parameters relate to the transport of data packets over a service provider""s network between specific entry and exit points. Measuring one way packet transport latency on per-packet instance basis and detecting instances of dropped packets is difficult because it requires correlation of per-packet information observed at both the entry and exit points. Such measurements are typically performed by an active experiment in which a known traffic pattern is injected into the entry point in order to assess the relationship between the packet""s instances injected into the network and their corresponding instances seen at the exit point. Measuring quality of service parameters through an active experiment does not represent a desired solution as the injected test traffic interferes with the regular operation of a monitored network.
What is required is a system and method to measure one way packet transport latency and detect incidents of packet dropping without using test patterns and through passive observations of regular customer traffic.
A method and system for passive quality of service monitoring of a network are described. In one embodiment, a number of signatures are extracted from a number of network packets at a number of monitoring points. In addition, at least one quality of service parameter is generated based upon the signatures.